Conventional optical couplers are used to combine or divide optical signal, for example an optic signal in a fiber optic cable. Conventional optical couplers are comprised of a plurality of fiber optic cables. Where an optical signal is to be split, the number of cables outputting a signal is greater than the number of cables inputting the signal. Similarly, where an optic signal is to be combined, the number of cables outputting a signal is less than the number of cables inputting the signal.
In order to form a conventional optic coupler, several fiber optic cables are fused together. In order to fuse the fibers, the fibers are typically placed in contact with each other, and heated and placed under tension. As the fibers are heated and drawn, the fibers fuse. To obtain a different number of input fibers than output fibers, a portion of each of a predetermined number of fibers is removed.
An important property of an optical coupler is reliability. For example, the Bellcore standard for fiber optic components provides several standards for optical coupler reliability, including temperature cycling, impact, and vibration standards. The impact, or mechanical shock standard, requires that optical couplers be capable of withstanding eight drops on each of three mutually perpendicular axes from a height of 1.8 meters (six feet). An optical coupler should be able to withstand having this impact test repeated five times. Similarly, optical couplers should pass a vibration test to meet Bellcore vibration standards. The vibration test provides a sinusoidal vibration having a frequency of ten Hertz to two thousand Hertz with an amplitude of 20G (or 1.52 millimeters or 0.0060 inches double amplitude). The frequency is swept from ten Hertz to two thousand Hertz and back within 20 minutes. This sweep cycle is repeated twelve times for in each of three mutually perpendicular directions to complete the test. An optical coupler should meet these standards.
Impact and vibration standards specify the impact and vibrations an optical coupler must withstand before failure. For example, when optical couplers are shipped to consumers, the couplers may be dropped. If the optical coupler cannot withstand the fall, it will fail. Similarly, the vibrations an optical coupler can withstand prior to failure affect its reliability.
Conventional optical couplers are able to withstand only a relatively small impact or small vibrations prior to failure. Thus, the reliability of typical optical couplers is greatly reduced by impacts or vibrations.
Accordingly, what is needed is a system and method for providing an optical coupler with increased resistance to failure due to impacts and vibrations and, therefore, greater reliability. The present invention addresses such a need.